What is an Outdoor Unit in an HVAC system?

The outdoor unit of a split system HVAC is the portion that contains the compressor and condenser. It is usually located outside the home, on a concrete pad, or in a metal cabinet. The outdoor unit is connected to the indoor unit (evaporator coil) by refrigerant lines. The outdoor unit also has electrical connections to provide power to the compressor and fan.

In a packaged system, all components are located in one cabinet, typically on the roof or at ground level next to the building. Packaged systems are used for larger commercial applications or when it is not possible to locate the outdoor unit away from the building (e.g., in an apartment complex).

  • The outdoor unit is responsible for pumping refrigerant to the indoor unit.
  • The compressor pressurizes the refrigerant, which then flows through the condenser coils.
  • The coils reject heat from the refrigerant to the outside air, causing the refrigerant to condense from a gas back into a liquid.
  • The condensed liquid refrigerant is then routed back to the evaporator coil in the indoor unit where the cycle starts anew.

The outdoor unit also contains a fan that blows air across the condenser coils and helps to remove heat from the refrigerant. The fan is usually located behind a louvered metal grille to protect it from damage and debris.

What is the difference between indoor and outdoor unit?

An indoor unit is an air conditioner or heat pump. A packaged system is one in which all components are located in one cabinet, typically on the roof or at ground level next to the building.


1) What is the outside unit of a heat pump called?

The outside unit of a heat pump is called the condenser. The condenser contains the compressor and fan, which are responsible for circulating refrigerant through the system.

2) Outside condenser unit not turning on?

  • If your outside condenser unit is not turning on, there could be a few reasons why. First, check to make sure that the power is turned on at the breaker box.
  • If the power is on, then check to see if there is a switch near the unit that has been turned off.
  • Finally, check the thermostat to make sure it is set to “cool” and set to a temperature lower than the current room temperature.

Related Links

HVAC Diagram

What is the Role of your Air Conditioner’s Outside Unit in the Cooling Process?

Related Videos